First you launch shinken with both NagiosRetention and PickleRetention modules. It will load data from NagiosRetention and save them in a more “efficient” file. So add in shinken-specififc.cfg file both modules for your scheduler object:

modules NagiosRetention ,PickleRetention

Then you remove the NagiosRetention (it’s a read only module, don’t fear for your nagios retention file) and restart with just PickleRetention. <code>modules PickleRetention